602 Heat and Cold Stress Safety

Glossary

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A

• Acclimatization. The physiological adaptation process that allows the body to gradually tolerate higher levels of heat stress, typically achieved over 7 to 14 days of progressive exposure. Acclimatized workers are more resistant to heat stress and perform better in hot environments.

B

• Baseline Temperature. The average temperature of the human body, typically around 98.6ºF (37ºC). Deviations from this baseline in cold or heat stress conditions can indicate the onset of health complications.
• Buddy System. A safety practice in which two workers monitor each other for signs of heat- or cold-related illnesses, enabling early intervention if symptoms are detected.

C

• Chilblains. A non-freezing cold injury characterized by redness, swelling, and itching of the skin due to prolonged exposure to cold, damp conditions. Symptoms usually affect the extremities, such as fingers, toes, and ears.
• Cold-Induced Diuresis. Increased urination caused by exposure to cold environments, leading to fluid loss and potential dehydration.
• Cold Stress. A condition where the body cannot maintain its normal temperature due to exposure to cold environments, potentially leading to hypothermia, frostbite, and trench foot. It occurs when the body loses heat faster than it can generate it.
• Conduction. The transfer of heat through direct contact with cold surfaces, such as holding cold tools or touching ice-cold metal. This is a significant contributor to heat loss in cold environments.
• Convection. The transfer of heat from the body to the surrounding air or water. Wind chill increases the rate of convection, leading to faster cooling of the body in cold environments.
• Core Body Temperature. The internal temperature of the body, which must be maintained within a narrow range (97ºF to 99ºF) to prevent heat or cold-related illnesses.

D

• Dehydration. A condition caused by excessive fluid loss, often due to sweating in hot environments or insufficient hydration in cold conditions. Dehydration exacerbates the effects of heat stress and increases the risk of heat-related illnesses.

E

• Evaporation. The process by which sweat on the skin cools the body. High humidity reduces evaporation, making it less effective at cooling and increasing heat stress risks.
• Exposure. The condition of being subjected to a potentially harmful physical, chemical, or biological agent.

F

• Frostbite. An injury caused by freezing of the skin and underlying tissues, leading to numbness, skin discoloration, and potential tissue damage. Severe frostbite can result in permanent damage or amputation.

G

• Gloves. Protective clothing worn on the hands to reduce the risk of frostbite in cold environments or burns from hot surfaces. Thermal and insulated gloves are commonly used in extreme conditions.
• Ground Temperature. The temperature of the earth's surface, which can influence workers exposed to hot or cold environments, especially in outdoor construction or farming activities.

H

• Heat Cramps. Painful muscle spasms caused by the loss of electrolytes and fluids through excessive sweating during strenuous activity in hot environments. They are often an early warning sign of heat stress.
• Heat Exhaustion. A heat-related illness characterized by heavy sweating, weakness, dizziness, nausea, and potential fainting. It occurs when the body becomes dehydrated and is unable to cool itself effectively.
• Heat Index. A measure that combines air temperature and relative humidity to estimate the apparent temperature, indicating how hot it feels to the human body. Used to assess heat stress risks.
• Heat Rash. A skin irritation caused by excessive sweating during hot, humid conditions. It manifests as red clusters of pimples or blisters, often on the neck, upper chest, or groin.
• Heat Stress. The total heat load on a worker from environmental factors, metabolic heat, and clothing. Excessive heat stress can lead to illnesses such as heat exhaustion or heat stroke.
• Heat Stroke. A severe, life-threatening heat-related illness characterized by a body temperature above 104ºF (40ºC), confusion, loss of consciousness, and potential organ failure. Immediate medical attention is critical.
• Hypothermia. A dangerous drop in body temperature below 95ºF (35ºC), caused by prolonged exposure to cold. Symptoms include shivering, confusion, and loss of motor skills. Severe cases can lead to unconsciousness or death.

I

• Incident. An occurrence, condition, or situation arising in the course of work that resulted in or could have resulted in injuries, illnesses, or damage.
• Incident Report. A detailed account of an accident or near-miss, documenting the events leading up to, during, and after the incident.
• Industrial Hygiene. The practice of identifying, evaluating, and controlling workplace conditions that may pose health risks, such as chemical, physical, or biological hazards.
• Injury Analysis. The examination of injuries sustained during an accident to determine the direct cause and contributing factors.
• Interim Measures. Temporary actions taken to control hazards until permanent solutions can be implemented.
• Interviewing Techniques. Methods and strategies used to effectively question witnesses and gather accurate information during an investigation.
• Intimidation. The act of making someone fearful or overawed, often hindering effective communication and cooperation during an investigation.
• Investigation. A systematic process of examining an accident to determine its causes and to identify measures to prevent recurrence.

J

• Job Hazard Analysis (JHA). A process that identifies potential workplace hazards associated with specific tasks and determines how to control or eliminate those risks.

K

• Kinetic (Impact) Energy. The energy possessed by an object due to its motion, which can cause injury upon impact.

L

• Layering. A cold stress prevention strategy involving wearing multiple layers of clothing to trap heat, allowing workers to adjust insulation based on activity levels and environmental conditions.

M

• Metabolic Heat. Heat generated by the body during physical activity. High levels of metabolic heat, combined with external heat sources, can increase the risk of heat-related illnesses.
• Moisture Wicking. A property of certain fabrics that pull sweat away from the skin, helping to regulate body temperature and reduce the risk of heat rash and discomfort.

N

• NIOSH. The National Institute for Occupational Safety and Health, a federal agency that researches and recommends measures to prevent work-related injuries and illnesses, including heat and cold stress.

O

• Overexertion. Physical strain or effort beyond one's capacity, often leading to musculoskeletal injuries.
• Overexposure. Excessive exposure to harmful substances or environments, such as chemicals, noise, or radiation, leading to health issues.

P

• Personal Protective Equipment (PPE). Specialized clothing and equipment, such as insulated jackets, cooling vests, or face shields, used to protect workers from extreme heat or cold environments.
• Preventive Measures. Strategies implemented to reduce the risk of heat and cold stress, such as hydration, rest breaks, acclimatization, and proper clothing.

Q

• Qualified Person. An individual with sufficient training, experience, or certification to perform specific tasks or inspections, as defined by OSHA.
• Quantitative Fit Test (QNFT). A method to assess the fit of a respirator using instruments to measure the amount of leakage into the facepiece.

R

• Radiant Heat. Heat emitted from a source, such as the sun, machinery, or fire. Radiant heat exposure increases the risk of heat-related illnesses in workers.
• Raynaud's Phenomenon. A condition in which small blood vessels in the fingers and toes overreact to cold, causing temporary loss of blood flow, numbness, and color changes in the affected areas.
• Rest Breaks. Scheduled periods of rest during work in extreme temperatures to allow the body to recover from heat or cold stress and prevent overexertion.
• Rhabdomyolysis. A serious condition caused by muscle breakdown due to extreme heat stress or physical exertion. It can result in kidney damage due to the release of muscle proteins into the bloodstream.

S

• Safe Work Practices. Established procedures and guidelines designed to ensure the safety and health of employees while performing their job tasks.

T

• Trench Foot. A non-freezing injury caused by prolonged exposure to wet, cold conditions. It leads to numbness, swelling, and tissue damage in the affected areas. Proper footwear and dry socks can prevent trench foot.

U

• Unsafe Behaviors. Actions by individuals that increase the risk of an accident or injury.

V

• Violation. A breach of safety regulations, standards, or policies, often resulting in disciplinary action or penalties.

W

• Warnings. Visual, auditory, or written alerts used to notify employees of potential hazards, such as signs, alarms, or color-coded labels.
• Workload. The amount of work assigned to or expected from an employee in a specific time period, which can impact safety and performance.

X

• Xerosis. An abnormal dryness of the skin that can occur in extreme cold environments, leading to cracking and irritation. Preventive measures include hydration and the use of moisturizers.

Y

• Yellow Flag Warning. A cautionary alert indicating moderate heat stress risk, often used in military or outdoor occupational settings to determine the need for preventive measures like hydration and reduced activity.

Z

• Zone Temperature Monitoring. The practice of assessing different areas of a workplace for temperature variations to identify zones of high heat or cold stress and implement appropriate controls.
• Zero Energy State. A condition achieved during cold stress-related maintenance where all energy sources (electrical or thermal) are isolated to ensure worker safety.